Uaty21(1).book(uaty_a_394748.fm)

Assistive Technology, 21:13–22, 2009Copyright 2009 RESNAISSN: 1040-0435 print DOI: 10.1080/10400430902945769
log , Vol. 21, No. 1, Apr 2009: pp. 0–0
Brad E. Dicianno, MD,1,2,3,4 Juliana Arva, MS, ATP,5 ABSTRACT
This document, approved by the Rehabilitation Engineering &
Jenny M. Lieberman, MS, OTR/L,
Assistive Technology Society of North America (RESNA) Board of Directors
ATP,6 Mark R. Schmeler, PhD, OTR/L, ATP,2,3,4 Ana Souza, MS,
on April 23, 2008, describes typical clinical applications and provides evidence
PT,2,3,4 Kevin Phillips, CRTS,7
from the literature supporting the application of tilt, recline, and elevating
Michelle Lange, OTR, ABDA, ATP,8 Rosemarie Cooper, MPT, ATP,2,3,4 Kim Davis, MS, PT, ATP,9 and Kendra L. Betz, MSPT, ATP10KEYWORDS
legrests, power features, recline, rehabilitation, tilt, wheelchair
1Department of Physical Medicine and Rehabiliation, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania2Center for Assistive Technology,
INTRODUCTION
University of Pittsburgh, Pittsburgh, Pennsylvania3
The purpose of this article is to share typical clinical applications as well as
provide evidence from the literature supporting the application of these
assistive technology interventions to assist practitioners in decision making
and justification. It is not intended to replace clinical judgment related to
Pennsylvania5Permobil, the Netherlands6Department of Rehabilitation, Mount Sinai Hospital, New York,
BACKGROUND
New York7Ability Center, San Diego, California
Wheelchair technology has evolved considerably in the past 15 years.
8Access to Independence, Inc., Arvada, Colorado
Several power and manual features can be added to a power wheelchair to
address a constellation of medical conditions. Previous position papers have
addressed the medical benefits of seat elevation and standing. Tilt, recline, and
elevating legrests are additional options that can be operated manually or that
come as power options. This position paper addresses the common medicalreasons for which these features are prescribed and the scientific and clinicalevidence for such prescriptions.
A wheelchair users’ survey study (Trail, Nelson, Van, Appel, & Lai, 2001)
examined the utility of various wheelchairs and their features and found that
tilt, recline, and elevating legrests were the most desirable features on a power
wheelchair. Manual- and power-operated features of power wheelchairs allow
Department of Physical Medicine and Rehabilitation, Kaufmann Medical
for changes in body and leg position and are features that have gained clinical
acceptance for people with disabilities who have limited ability to reposition
Pittsburgh, PA 15213. E-mail: dicianno@pitt.edu
or reorient their bodies independently.
Changes in body position are necessary to address
manual features so that a caregiver can assist with posi-
issues related to postural alignment, function, physiol-
tioning and care of the wheelchair user. These manual
ogy, transfers and biomechanical issues, contractures
features are beneficial if the individual needs reposi-
or orthopedic deformities, edema, spasticity, pressure
tioning many times throughout the day. However,
management, comfort, or dynamic movement. Many
if the wheelchair user can operate power features
payer sources and reviewers often believe that tilt and
independently, then those are most appropriate and
recline are interchangeable. While they may comple-
ment each other, they are not interchangeable and servevery unique medical purposes.POSTURAL REALIGNMENT AND FUNCTIONDEFINITIONS
Tilt and recline provide a means for gravity-assisted
positioning. Some manufacturers allow for a fixed
• Tilt systems change seat angle orientation in relation
recline angle to be crafted into the wheelchair frame
to the ground while maintaining the seat to back
(Lange, 2000b; Sommerfreund & Masse, 1995). This is
and seat to legrest angles. Traditional tilt operates in
useful when the individual needs a degree of recline to
the sagittal plane, while lateral and rotational tilt
accommodate trunk positioning, and this feature can
systems operate in the coronal or oblique planes,
be combined with a tilt system. However, the majority
of individuals generally need recline angles that can be
• Recline systems provide a change in seat to back
changed, especially if they spend most of their time in
angle orientation while maintaining a constant seat
the wheelchair. Clinicians recommend that users with
poor trunk or head control alter their center of gravity
• Elevating legrests allow individuals to change the
by altering tilt and recline angles to gain balance and
angle of orientation of the legs and/or footrests relative
stability (Kreutz, 1997; Lange, 2006). Postural align-
to the seat, extending the knee. Some legrests are
ment is especially important for children or adults
articulating, which means they lengthen while also
with progressive or static scoliosis (Lange, 2000b).
According to many clinicians, tilt is useful for those
with contoured seat backs since it maintains theappropriate angles for clients to remain in contact
MANUAL OR POWER FUNCTIONS?
with the shape of the backrest (Kreutz, 1997). Because
Tilt, recline, and elevating legrests are available as
some recline systems cause shear forces against the
either manual- or power-operated features. They serve a
individual’s back, the problem of shear can be further
variety of medical purposes, which are described below.
compounded with a contoured backrest. The interface
Clinicians prescribe power features if an individual’s
between the client and seat back can then be suboptimal.
medical condition is such that he or she would benefit
However, recline systems reported in the clinical liter-
from one of these features but is not able to operate the
ature (Kreutz, 1997; Pfaff, 1993) are available that
manual feature independently due to a constellation of
allow the molded back to track along with clients as
cognitive, motor, or sensory impairments. These power
they recline, maintaining the seat interface. The clini-
features are generally medically necessary as long as the
cian should ensure that the client stays in position
individual can operate the power version and has medi-
when using any recline system with a molded back
cal reasons for their use. Age should not be used as a
and should consider using tilt in combination with
determinant for whether or not an individual is capable
of operating power features; the elderly and young alike
One benefit of proper alignment is enhancement of
are often able to use power features adequately. Rather,
function (Nwaobi, 1987). For example, tilting anteriorly
clinicians must evaluate each client’s medical and social
may be clinically beneficial to assist with functional
situation on a case-by-case basis (Kreutz, 1997; Lange,
reaching. Use of legrests and footrests has been shown
to improve balance, completion of activities of daily
If an individual is unable to operate power or manual
living (ADLs), and maintenance of safe positioning
features independently, it may be necessary to prescribe
during braking (R. A. Cooper, Dvorznak, O’Connor,
B. E. Dicianno et al.
Boninger, & Jones, 1998; Janssen-Potten, Seelen,
Visual Orientation, Speech,
Drukker, Spaans, & Drost, 2002). Tilt or elevating leg-
Alertness, Arousal, Respiration,
rests can enable ground clearance for those with low
and Eating
seat heights who encounter obstacles or can improveaccess to load the chair into a vehicle. Those who
Some individuals may also need tilt and recline for
maintain the legs in an elevated position may need
visual orientation, speech, alertness, and arousal. It has
power features to change the position of the legrests
been documented clinically that tilt and recline
regularly throughout the day in order to negotiate
systems can be used to orient the trunk and head
obstacles for clearance. Tilt can be used to promote
position (Kreutz, 1997; Lange, 2000a), stimulate the
stability in the chair when an individual tends to slide
vestibular system (Lange, 2000a), improve line of sight
out of the chair due to extensor tone of the back or
(Kreutz, 1997), and allow for better communication
contractures. Individuals also sometimes use tilt for
(Kreutz, 1997). Providing a slightly tilted or reclined
stability when driving downhill or when carrying
position with headrest support can prevent neck
hyperextension if neck flexors are weak. On the other
Power features are especially important for pediatric
hand, individuals whose neck and trunk are too flexed
users to allow them better access to their environment.
when sitting upright may need further tilt or recline
More accessible environments may allow for early
to encourage extension. Clinicians use customized
stimulation, which is important for achieving develop-
positioning to maximize breathing and speaking ability
mental milestones, especially among children with
by maintaining vital organ capacity and to reduce risk
disabilities (Garcia-Navarro et al., 2000).
for aspiration (D. Cooper, 2004; Hardwick, 2002;Lange, 2006). Therapists also sometimes use positioningfor stimulation of digestion after meals (D. Cooper,
PHYSIOLOGICAL IMPLICATIONS
Proper postural alignment may also aid in main-
taining vital organ capacity and has several physio-
Bowel and Bladder Management
logical implications (Lacoste, Weiss-Lambrou, Allard, &Dansereau, 2003; Nwaobi, 1987), as documented
Some bowel and bladder management techniques
such as changing protective undergarments or inter-mittent self-catheterization require supine positioning(Wyndaele, 2002). Some individuals cannot comply
Orthostatic Hypotension
with their recommended programs because they cannot
The prevalence of orthostatic hypotension is high
position themselves appropriately and may require
in the general population (Bradley & Davis, 2003), but
additional assistance (Wyndaele, 2002). Noncompli-
it especially affects individuals with such conditions
ance with bladder programs may result in increased
as cardiac disease, spinal cord injury (SCI), diabetes,
urinary tract infections and, ultimately, increased mor-
neuropathy, multiple sclerosis, and Parkinsonism.
bidity, including renal complications (Salomon et al.,
Part of the management of acute symptoms such as
2006). Individuals with indwelling catheters may expe-
dizziness includes assuming a recumbent or semire-
rience backflow of urine when using a tilt system.
cumbent position (Claydon, Steeves, & Krassioukov,
However, using features such as recline may allow
2006). Clinicians suggest that using a combination of
individuals to perform their care independently and
tilt, recline, and power legrests can help to achieve
reduce the need for caregiver assistance.
such a position (Kreutz, 1997). One cross-sectionalstudy that evaluated several interventions for orthos-
TRANSFERS AND BIOMECHANICAL
tasis (Kreutz, 1997; Ten Harkel, Van Lieshout, &
Wieling, 1992) showed that sleeping in bed with thehead elevated at 10° to 20° improves symptoms. More
Positioning may also be necessary in order to
research is needed to determine if positioning during
improve transfer biomechanics of both the wheelchair
the day, such as in power wheelchairs, might be of
user and the caregiver. When an individual is indepen-
additional benefit for long-term management.
dently transferring from an upright position, the
Tilt, Recline, and Elevating Legrests for Wheelchairs
shoulder can experience forces as high as two and a
or orthopedic deformities (Levy, Berner, Sandhu,
half times mean arterial pressure (Bayley, Cochran, &
Sledge, 1987). People can use tilt and recline to stabilize
Therapists also use elevating legrests to provide
their trunk in order to position themselves properly
passive movement to the knee joints (Lange, 2006).
for a transfer. Reducing load by adjusting the center
When contractures are present, the legrests should be
of gravity during an independent or assisted transfer
adjusted to the appropriate accommodative angle to
may reduce the risk for upper limb pain and injury
prevent undue tension in the hamstrings and hip
(Herberts, Kadefors, Hogfors, & Sigholm, 1984).
joints. It is recommended that elevating legrests be
Recline may be used in combination with elevating
used in combination with recline when passive exten-
legrests to enhance sliding transfers with a person in
sion of the knee is limited due to hamstring tightness,
supine position. Anterior recline (“precline”) can add
as recline allows extension of the hip. Additional foot-
momentum to the trunk for transfers. Anterior tilt can
plate extensions or angle changes might be necessary.
be used with a seat elevator to improve transfers from
Extending the knee near end range, however, can
and to elevated positions or to reduce shoulder load
often elicit reflex spasticity in those with central
when activities would otherwise need to be performed
nervous system disorders. Tilt systems with adjustable
with arms overhead. Reducing this load is vitally
seat and back angles are also useful for positional
important for preservation of upper limb function
changes in those with limited hip range of motion.
Those with limited hip flexion can use tilt and/or
Better biomechanical position not only reduces the
recline systems when the seat to back angle is appropri-
need for assistance with ADLs and transfers but also
ately configured. In some cases, therapists must set a
reduces the risk of injury to caregivers (Edlich,
limit to prevent closing of seat to back angle beyond the
Heather, & Galumbeck, 2003; Fragala & Bailey, 2003).
available hip range of motion so that excess force is not
Furthermore, by prolonging sitting tolerance with use
placed on the hips and the user is not pushed out of the
of power features, the number of times a person may
seat (Kreutz, 1997). However, some people need to bring
need to be transferred can be reduced.
their trunk more upright for limited periods of time toengage in ADLs such as reaching. The impact of seat toback angle on function must always be considered.SPASTICITY
Offering a client the ability to change joint angles
can allow independent management of tone. Becausetilt systems maintain static joint angles and thus muscle
Clinicians also use power elevating legrests to man-
fiber length, clinicians use these features in those with
age edema (Kreutz, 1997; Levy et al., 1999). The lower
spasticity to offer positional changes without eliciting
limbs of wheelchair users may act as a reservoir for
increases in tone (Kreutz, 1997). Clinically, recline
fluid accumulation (Kinzer & Convertino, 1989).
systems should be considered on a case-by-case basis for
Elevation of the legs above the level of the left atrium
management of spasticity since it has been noted that
by about 30 cm is generally recommended as part of
in some individuals recline can increase tone, especially
the management of edema in conjunction with, rather
in the spine extensors (Kreutz, 1997; Lange, 2006).
than in lieu of, other measures such as support gar-ments (Abu-Own, Scurr, & Coleridge Smith, 1994;Douglas & Simpson, 1995; O’Brien, Chennubhotla, &
CONTRACTURES AND ORTHOPEDIC
Chennubhotla, 2005). This allows for reduction in
DEFORMITIES
venous pressure and increases arterio-venous pressureand capillary flow. Elevating legrests, therefore, are
Clinicians argue that static seating systems can
most effective when used in combination with tilt to
sometimes lead to contractures, especially in the ham-
allow elevation of the legs above heart level. Some tilt
strings (Lange, 2006). Power elevating legrests are
systems, when combined with elevating legrests, still
often medically necessary when an individual cannot
do not allow for adequate leg elevation above the
independently operate manual legrests but needs to
heart, and in these cases elevating legrests must be
elevate the lower limbs to manage contractures
combined with tilt and recline systems.B. E. Dicianno et al.PRESSURE RELIEF
even the best pressure relief cushions are inadequateto prevent pressure ulcers if the individual sits on
Studies comparing seating pressure among subjects
them too long without adequate position changes
with SCI, spina bifida (SB), and control subjects
(Lacoste et al., 2003). Therefore, current accepted
(Aissaoui, Kauffmann, Dansereau, & de Guise, 2001;
practice is to provide a combination of cushion tech-
Hobson, 1992; Vaisbuch, Meyer, & Weiss, 2000) have
nology and means for position changes in order to
shown that individuals with disabilities experience
prevent and treat pressure ulcers (Henderson, Price,
seating pressures that are significantly higher or focused
over smaller surface areas than those experienced byindividuals without disabilities. A tissue’s tolerance forpressure depends on the disability type as well as a
Wheelchair Push-Ups
number of additional factors, including age, nutrition,
Clinicians often prescribe power features when an
temperature, anatomical location, moisture, presence
individual cannot transfer into and out of the chair
of incontinence, and tissue metabolism (Edlich et al.,
independently. This is based on the assumption that
prolonged sitting increases risk for skin breakdown and
A key component in preventing and managing pres-
limitations in ability to transfer preclude adequate
sure ulcers involves the use of various support surfaces
weight shifting capability. There is, in fact, a wealth of
and position changes to reduce forces. There are two
scientific evidence to support this notion, but transfer
different types of forces that act on tissues (Sprigle,
ability is not the only factor that should be considered.
2000). “Normal” force acts perpendicularly to the skin
Many wheelchair users perform wheelchair “push-ups”
surface. “Shear” force acts tangentially to the skin
as a way to alleviate pressure. Most individuals perform
surface and/or deeper tissues. Both can occlude blood
such maneuvers for approximately 15–30 seconds
and lymph vessels. Friction is a type of shear force that
(Coggrave & Rose, 2003), but frequency is variable,
acts at the interface between the skin and supporting
with recommendations ranging from one shift every
tissues. When shear occurs, the magnitude of the load
minute to one per hour (Boninger & Stripling, 2007;
needed to cause ischemia is reduced to half (Bennett,
Paralyzed Veterans of America, 2000; Vaisbuch et al.,
2000). In one retrospective review article (Coggrave &
Valid and reliable outcome measures for seating
Rose, 2003), transcutaneous oxygen tension of 46 sub-
pressure have not always governed clinical practice.
jects performing wheelchair push-ups was measured. It
Conventionally, manufacturers of pressure-relief prod-
was reported that each lift needed to last nearly 2 min-
ucts have felt that any load that exceeds 32 mmHg is
utes, regardless of frequency, in order to return tissues
harmful. This value came from a historical article in
to unloaded levels. This is clearly impossible, imprac-
1930 (Landis, 1930) that calculated the capillary pressure
tical, and undesirable for any wheelchair user, even
of the fingernail bed to be approximately 32 mmHg,
users with healthy upper limbs and joints. In fact, the
as well as from microscopic studies (Kosiak, 1959,
load on the shoulder and arms during these maneu-
1961) in which 32 to 40 mmHg was considered a safe
vers increases substantially and may predispose people
threshold. However, to date, no research has produced
to repetitive strain injuries (Bayley et al., 1987; Reyes,
a cutoff value for load that is known to be causative
Gronley, Newsam, Mulroy, & Perry, 1995). Thus,
for ulcer formation. In fact, one reliability study on
many clients who cannot transfer independently, and
pressure testing (Sprigle, Dunlop, & Press, 2003)
even some of those who can, need power seat func-
showed that peak pressure is not a reliable outcome
measure and suggested that the use of other, more reli-able measures, including average pressure, may be
Forward and Side Leaning
more appropriate. One retrospective review of tissueoxygen measurement techniques (Coggrave & Rose,
Several of the studies done in SCI and SB on seating
2003) used transcutaneous oxygen tension as a reliable
pressures (Coggrave & Rose, 2003; Henderson et al.,
means of determining load on the tissue.
1994; Hobson, 1992; Vaisbuch et al., 2000) have
Duration of the load is also a factor in ulcer forma-
shown that forward and side-to-side leaning can be
tion (Sprigle, 2000). Many clinicians maintain that
effective methods for relieving pressure over the
Tilt, Recline, and Elevating Legrests for Wheelchairs
ischial tuberosities. However, not all individuals who
recline can increase normal forces at the ischial tuber-
use wheelchairs have the arm strength or trunk control
osities (Gilsdorf, Patterson, Fisher, & Appel, 1990), so
required to perform these maneuvers independently
clinicians often recommend using tilt before return to
(Lacoste et al., 2003) or may not be able to do so due
upright to minimize shear. Elevating legrests may also
to autonomic dysreflexia or neurogenic bladder (Vais-
help in alleviating ischial and foot support pressure
buch et al., 2000). Moreover, these maneuvers may
(Aissaoui, Heydar, Dansereau, & Lacoste, 2000) and
not be effective when used with some cushions (Koo,
can help reduce shear along the entire seating surface
Mak, & Lee, 1996). For those individuals who cannot
(Carlson, Payette, & Vervena, 1995). The aforemen-
perform adequate weight shifting, current clinical
tioned “shear-reducing” recline systems (Pfaff, 1993)
practice is to promote pressure relief by providing
are thought to reduce shear forces, but at the time of
power features that the user can operate indepen-
this writing the only supporting evidence was anec-
dently (Lacoste et al., 2003; Vaisbuch et al., 2000).
dotal. Yet, their utility is especially important clini-cally when they allow the user to remain in contactwith the seat back for positioning purposes.Power Features for Pressure Relief
Simply providing these power features when they
Tilt and recline features provide the most pressure
are medically necessary may not be adequate; training
relief when used in combination. One study (Vaisbuch
and follow-up are important. One survey study
et al., 2000) found significantly lower maximum pres-
(Lacoste et al., 2003) showed that although 97.5% of
sure in the combined position of 25° of tilt with 110°
individuals who had tilt and recline used these
of recline in subjects with SB. A study in subjects with-
features every day, less than 35% used these features
out impairments (Aissaoui, Lacoste, & Dansereau,
primarily for pressure relief but, rather, also to reduce
2001) showed that 45° of tilt with 120° of recline pro-
pain and promote comfort. The majority of individu-
vided a 40% load reduction. A study on two subjects
als used angles that were inadequate for pressure relief.
with tetraplegia (Pellow, 1999) showed a trend toward
There is also insufficient research that documents the
interface pressure reduction with a combination of 45°
appropriate duration and frequency of use of these
features, but clinicians sometimes estimate a duration
Tilt alone may also confer some advantage for pres-
of 30 seconds with a frequency of 15–30 minutes or
sure relief. Significant ischial pressure relief has been
60 seconds every 60 minutes to be a conservative
shown at 65° of tilt (Henderson et al., 1994) and lower
estimate given the research on wheelchair push-ups
shear forces noted even at 25° (Hobson, 1992). How-
and clinical practice guidelines published for SCI
ever, one study showed that 15° or less provides no
(Coggrave & Rose, 2003; Paralyzed Veterans of America,
advantage in terms of pressure reduction (Aissaoui,
2000; Vaisbuch et al., 2000). This evidence substantiates
Lacoste, & Dansereau, 2001) but may have benefits for
the need for follow-up visits with clients for extended
postural stability. Power lateral and rotational tilt can
be beneficial in adding more degrees of freedom tothe maneuvers available.PAIN, FATIGUE, AND SITTING
When effects of elevating legrests on posture were
TOLERANCE
studied in subjects without impairments (Stinson,Porter-Armstrong, & Eakin, 2003), it was found that
Although clinicians may configure seating systems
120° of recline in combination with elevation of legs
according to body dimensions, the types of seating
can significantly reduce seating interface pressure.
systems people find comfortable may be quite differ-
When used alone, recline tends to reduce normal
ent from what their anthropometry may predict
force but increase shear (Hobson, 1992), especially
(Kolich, 2003). Ergonomic literature on drivers sug-
when individuals recline to 110° and 120° (Aissaoui,
gests that seating systems should not be configured
Lacoste, & Dansereau, 2001). Care must be taken with
solely based on static postures. Instead, sitting tolerance is
sole prescription of recline because when used in isola-
a dynamic phenomenon that requires a dynamic
tion it may put a client at risk for skin breakdown,
assessment (Porter, Gyi, & Tait, 2003). Clinicians face
especially if the client does not know how to use it
time constraints when doing seating evaluations. The
properly. Additionally, return to upright position after
most experienced clinicians doing thorough evaluations
B. E. Dicianno et al.
are still not always able to assess all of the sitting
for individuals who use office furniture and worksta-
postures the client will undoubtedly need to assume in
tions (Kroemar, 1994) and should undoubtedly be
daily life in a routine evaluation. In fact, many individ-
applied to wheelchairs as well, since many wheelchair
uals’ postures are so variable that more than 2 hours are
users may not have the same level of dynamic move-
needed to observe the critical seating postures an indi-
ment as able-bodied office workers. Power tilt, recline,
vidual assumes to remain comfortable (Gyi & Porter,
and elevating legrests can provide individuals who use
1999). This suggests that power features, when used to
wheelchairs with a means of providing and assisting
promote dynamic sitting tolerance, may be useful to
assume many postures beyond those seen in a clinical
Dynamic movement is healthy for the spine. Chair
assessment. If power features are not available, and
designs that allow passive motion during seating may
high interface pressures are present, individuals may
actually help to prevent back pain (Reinecke, Hazard, &
seek alternative postures that may prolong sitting
Coleman, 1994). The loading and unloading of inter-
tolerance but are poor for overall postural alignment,
vertebral discs that occur during dynamic repositioning
skeletal development, or function or may hasten the
of the spine may increase nutrient supply to the discs
(Andersson, 1981; Kolditz, Kramer, & Gowin, 1985).
While there is some disagreement in the literature
Indeed, this has also been shown in animal (Holm &
about what reduces sitting tolerance, higher pressure
Nachemson, 1983) and cadaveric (Adams & Hutton,
has been found to be a significant factor (de Looze,
1983) models. Prolonged static sitting without appro-
Kuijt-Evers, & van Dieen, 2003; Goossens, Teeuw, &
priate back support can increase risk for herniated
Snijders, 2005). Interestingly, in the aforementioned
discs (Adams, Green, & Dolan, 1994; Kelsey, 1975)
survey study (Lacoste et al., 2003), power wheelchair
because, when an individual slumps, his or her spine
users stated that they primarily used their features to
is flexed, and the anterior annulus experiences a com-
promote comfort and reduce back and joint pain.
pressive force about 50% higher than when the spine
Indeed, the ergonomic literature on automobile driving
is naturally erect (Adams & Hutton, 1985). Reduction
suggests back pain is one of the most common symptoms
in the lumbar curvature during slumping may shift the
of sitting, especially when seating is not adjustable
load to ligaments, which can then deform the spine
(Porter & Gyi, 2002). Distance traveled while driving
(Kumar, 2004). In addition, while the apophyseal
and the number of hours spent sitting are significantly
joints can resist intervertebral shear force when the spine
related to low back pain (Gyi & Porter, 1998; Porter &
is flexed, they are less able to resist compressive force
than when in the erect position (Adams & Hutton,1985).
Even when the pelvis is stabilized on the seat, if the
DYNAMIC MOVEMENT
backrest is supported at less than 110° of recline, the
When allowed to move freely, people are usually in
pelvis can still rotate posteriorly, resulting in flattening
constant motion (Branton, 1969). It is difficult for
of the lumbar spine (Bendix & Biering-Sorensen, 1983;
most individuals to tolerate unsupported and static
Nachemson, 1981), just as in unsupported sitting.
seated positions for more than a short while (Reinecke,
Thus, the pelvis must be supported and the thigh to
Bevins, Weisman, Krag, & Pope, 1985). People generally
torso angle must be a minimum of 110° to keep
change postures up to 30 times per hour while sitting
the natural curve of the lumbar spine (Andersson,
(Graf, Guggenbuhl, & Kreuger, 1991). Static seating
Murphy, Ortengren, & Nachemson, 1979; Keegan,
systems can restrict an individual from assuming the vari-
1953; Lueder, 2005; Nachemson, 1981). However,
ety of postures that are natural for the body (Bendix &
individuals in the reclined position also must reach
Biering-Sorensen, 1983) and may cause the body to
farther to perform ADLs, increasing the load on shoul-
move into postures that are harmful (Bhatnager, Drury, &
ders and arms (Lueder, 2005) as well as the cervical
Schiro, 1985). The only effective way to endure a
spine (Grandjean, Hunting, & Pidermann, 1983). Also,
seated posture for an extended period of time and to be
tilting a seat with a static back angle has been shown to
productive and functional in that posture is to change
cause increased thoracic flexion instead of extension
positions constantly (Lueder, 2005). The concept of
(Engstrom, 1993). Therefore, in order to perform a
“dynamic sitting” is endorsed in the ergonomic field
variety of functional tasks comfortably and safely,
Tilt, Recline, and Elevating Legrests for Wheelchairs
most users will need varying degrees of recline. For a
legrests. Tilt was used in conjunction with recline for
wheelchair user who is not able to independently cycle
pressure relief. Tilt and elevating legrests were used
through a range of positions using a manually adjustable
together to manage edema more effectively. After
recline system but who needs to perform a host of func-
6 months of use, she noted marked improvement in
tional tasks from the wheelchair, the solution is to use
edema, and her wound closure remained intact. She
power-operated recline. Obviously, a clinician must con-
also now is able to catheterize herself while in her
sider how shear forces may act in these cases and reserve
chair, which she finds very useful when she is at work.
recline systems for those who can operate them safely
Louis is an 85-year-old man with a history of an
and consider tilt in combination with recline.
ischemic stroke and left hemiparesis. He developedspasticity of the left hemibody that has been unre-sponsive to treatment with botulism toxin. His tone
fluctuates, but he notes less spasticity and clonus
Tilt, recline, and elevating legrests may be useful
when his legs are elevated. He can no longer ambulate
and medically necessary to address issues related to
but is able to stand pivot transfer independently. He
postural alignment, function, physiology, transfers
lacks dexterity in his left hand to operate manual leg-
and biomechanical issues, contractures or orthopedic
rests or hand propel his current manual wheelchair
deformities, edema, spasticity, pressure management,
and can no longer use foot propulsion for mobility.
comfort, or dynamic movement. However, they are not
He was prescribed a power wheelchair with recline and
required for or desired by everyone; therefore clinical
power elevating legrests to manage tone and accom-
judgment is required in prescription. RESNA therefore
modate knee flexion contractures. With frequent repo-
recommends power tilt, recline, and elevating legrests
sitioning of his limbs, Louis has noted an improvement
when such features are needed to treat or prevent the
medical issues described above and when the user can-
Yolanda is a 46-year-old woman with spastic athetoid
not operate the manual versions of these features.
cerebral palsy. She is not able to self-propel a manual
While some of the recommendations for use of tilt,
wheelchair and is not independent with power mobility.
recline, or elevating legrests are based on clinical
Her caregivers are propelling her in a depot-style manual
observations, the use of these features is also substanti-
wheelchair. They note that she slides out of the chair
ated by a wealth of scientific literature that stems from
due to extensor tone and coughs and gags when eating
research on sitting postures, interface pressures, ergo-
because of her slumped position. She is prescribed an
nomics, and user surveys. Provision of one or all of
attendant-propelled manual wheelchair with a manual
these features may improve an individual’s sitting
tilt-in-space feature that helps keep her from sliding
tolerance and overall quality of life by increasing
out of her chair. Yolanda does not have as much diffi-
function and reducing pain, as well as reducing or
culty eating when her position can be changed so that
delaying secondary complications from long-term
Hank is a 32-year-old man with a C6 ASIA A SCI.
He uses a power wheelchair with tilt, recline, andpower elevating legrests to control edema and spasticity
CASE EXAMPLES
and to provide pressure relief. He is being evaluated
Julie is a 24-year-old woman with SB. She recently
for a new power chair because of electrical problems.
developed chronic pressure ulcers on the bilateral
He has noted a progression in his scoliosis since his
ischial tuberosities requiring flap surgery. She presents
last visit, and a significant trunk lean interferes with
for a new power wheelchair because hers is now in
functional use of his arms. He is prescribed a new
disrepair. She has been using a power wheelchair with
power chair with the same features, but this time,
pressure relief cushion and manually elevating legrests
power lateral tilt is added. He typically uses slight
to control edema but has no power features. She now
lateral tilt at all times to improve trunk position, but
cannot operate the manual legrests because of carpal
also often independently adjusts the tilt to aid in pres-
tunnel syndrome. She transfers out of the chair to
sure relief and stability. He has noted an improvement
catheterize herself. She was prescribed a new power
in reaching, comfort, and use of his computer access
wheelchair with tilt, recline, and power elevating
B. E. Dicianno et al.REFERENCES
Edlich, R. F., Heather, C. L., & Galumbeck, M. H. (2003). Revolutionary
advances in adaptive seating systems for the elderly and persons
Abu-Own, A., Scurr, J. H., & Coleridge Smith, P. D. (1994). Effect of leg
with disabilities that assist sit-to-stand transfers. Journal of the Long
elevation on the skin microcirculation in chronic venous insufficiency.Term Effects of Medical Implants, 13, 31–39.Journal of Vascular Surgery, 20, 705–710.
Edlich, R. F., Winters, K. L., Woodard, C. R., Buschbacher, R. M., Long,
Adams, M., & Hutton, W. (1983). The effect of posture on the fluid
W. B., Gebhart, J. H., et al. (2004). Pressure ulcer prevention. Journal
content of lumbar intervertebral discs. Spine, 8, 665–671.of the Long Term Effects of Medical Implants, 14, 285–304.
Adams, M., & Hutton, W. (1985). The effect of posture on the lumbar
Engstrom, B. (1993). Fundamental seating principles, correcting the
spine. Journal of Bone & Joint Surgery, British Volume, 67, 625–629.trunk. Retrieved from http://www.posturalis.se/eng/EngView.pdf
Adams, M. A., Green, T. P., & Dolan, P. (1994). The strength in anterior
Fragala, G., & Bailey, L. P. (2003). Addressing occupational strains and sprains:
bending of lumbar intervertebral discs. Spine, 19, 2197–2203.
Musculoskeletal injuries in hospitals. AAOHN Journal: Official Journal of
Aissaoui, R., Heydar, S., Dansereau, J., & Lacoste, M. (2000).the American Association of Occupational Health Nurses, 51, 252–259.
Biomechanical analysis of legrest support of occupied wheelchairs:
Garcia-Navarro, M. E., Tacoronte, M., Sarduy, I., Abdo, A., Galvizu, R.,
Comparison between a conventional and a compensatory legrest.
Torres, A., et al. (2000). Influence of early stimulation in cerebral
IEEE Transactions on Rehabilitation Engineering, 8, 140–148.
palsy. Revista de Neurologia, 31, 716–719.
Aissaoui, R., Kauffmann, C., Dansereau, J., & de Guise, J. A. (2001).
Gilsdorf, P., Patterson, R., Fisher, S., & Appel, N. (1990). Sitting forces
Analysis of pressure distribution at the body-seat interface in able-
and wheelchair mechanics. Journal of Rehabilitation Research and
bodied and paraplegic subjects using a deformable active contour
Development, 27, 239–246.
algorithm. Medical Engineering and Physics, 23, 359–367.
Goossens, R. H., Teeuw, R., & Snijders, C. J. (2005). Sensitivity for pres-
Aissaoui, R., Lacoste, M., & Dansereau, J. (2001). Analysis of sliding and
sure difference on the ischial tuberosity. Ergonomics, 48, 895–902.
pressure distribution during a repositioning of persons in a simulator
Graf, M., Guggenbuhl, H., & Kreuger, H. (1991). Movement dynamics of
chair. IEEE Transactions on Neural Systems and Rehabilitation Engi-
sitting behaviour during different activities. In Y. Queinnec &
neering, 9, 215–224.
F. Daniellou (Eds.), Designing for everyone: Proceedings of the 11th
Andersson, G. B. (1981). Epidemiologic aspects on low-back pain in
Congress of the International Ergonomics Association (pp. 15–17).
industry. Spine, 6, 53–60.
Andersson, G. B., Murphy, R. W., Ortengren, R., & Nachemson, A. L.
Grandjean, E., Hunting, W., & Pidermann, M. (1983). VDT workstation
(1979). The influence of backrest inclination and lumbar support on
design: Preferred settings and their effects. Human Factors, 25, 161–175.
lumbar lordosis. Spine, 4, 52–58.
Gyi, D. E., & Porter, J. M. (1998). Musculoskeletal problems and driving
Bayley, J. C., Cochran, T. P., & Sledge, C. B. (1987). The weight-bearing
in police officers. Occupational Medicine, 48, 153–160.
shoulder: The impingement syndrome in paraplegics. Journal of
Gyi, D. E., & Porter, J. M. (1999). Interface pressure and the prediction of
Bone and Joint Surgery, American Volume, 69, 676–678.
car seat discomfort. Applied Ergonomics, 30, 99–107.
Bendix, T., & Biering-Sorensen, F. (1983). Posture of the trunk when
Hardwick, K. (2002). Insightful options. Rehab Management. Retrieved
sitting on forward inclining seats. Scandinavian Journal of Rehabilation
from http://www.rehabpub.com/features/102002/4.asp
Medicine, 15, 197–203.
Henderson, J. L., Price, S. H., Brandstater, M. E., & Mandac, B. R. (1994).
Bennett, L., Kavner, D., Lee, B. K., & Trainor, F. A. (1979). Shear vs
Efficacy of three measures to relieve pressure in seated persons with
pressure as causative factors in skin blood flow occlusion. Archives of
spinal cord injury. Archives of Physical Medicine and Rehabilitation,
Physical Medicine and Rehabilitation, 60, 309–314.
Bhatnager, V., Drury, C. G., & Schiro, S. G. (1985). Posture, postural
Herberts, P., Kadefors, R., Hogfors, C., & Sigholm, G. (1984). Shoulder
discomfort, and performance. Human Factors, 27, 189–199.
pain and heavy manual labor. Clinical Orthopaedics and Related
Boninger, M., & Stripling, T. (2007). Preserving upper-limb function in
Research, 191, 166–178.
spinal cord injury. Archives of Physical Medicine and Rehabilitation,
Hobson, D. A. (1992). Comparative effects of posture on pressure and
shear at the body-seat interface. Journal of Rehabilitation Research
Bradley, J. G., & Davis, K. A. (2003). Orthostatic hypotension. Americanand Development, 29(4), 21–31.Family Physician, 68, 2393–2398.
Holm, S., & Nachemson, A. (1983). Variations in the nutrition of the
Branton, P. (1969). Sitting posture. In E. Grandjean (Ed.), Proceedings of
canine intervertebral disc induced by motion. Spine, 8, 866–874.a symposium held in September 1958 at the Swiss Federal Institute
Janssen-Potten, Y. J., Seelen, H. A., Drukker, J., Spaans, F., & Drost, M. R.of Technology (pp. 202–213). London: Taylor & Francis.
(2002). The effect of footrests on sitting balance in paraplegic sub-
Carlson, J. M., Payette, M. J., & Vervena, L. (1995). Seating orthosis
jects. Archives of Physical Medicine and Rehabilitation, 83, 642–648.
design for prevention of decubitus ulcers. Journal of Prosthetics and
Keegan, J. (1953). Alterations of the lumbar curve related to posture and
Orthotics, 7(2), 51–60.
seating. Journal of Bone and Joint Surgery, 35, 589.
Claydon, V. E., Steeves, J. D., & Krassioukov, A. (2006). Orthostatic
Kelsey, J. L. (1975). An epidemiological study of the relationship
hypotension following spinal cord injury: Understanding clinical
between occupations and acute herniated lumbar intervertebral
pathophysiology. Spinal Cord, 44, 341–351.
discs. International Journal of Epidemiology, 4, 197–205.
Coggrave, M. J., & Rose, L. S. (2003). A specialist seating assess-
Kinzer, S. M., & Convertino, V. A. (1989). Role of leg vasculature in
ment clinic: Changing pressure relief practice. Spinal Cord, 41,
the cardiovascular response to arm work in wheelchair-dependent
populations. Clinical Physiology, 9, 525–533.
Cooper, D. (2004). A retrospective of three years of lateral tilt-in-space.
Kolditz, D., Kramer, J., & Gowin, R. (1985). Water and electrolyte con-
Proceedings of the International Seating Symposium, 20, 205–209.
tent of human intervertebral disks under varying load. Zeitschrift für
Cooper, R. A., Dvorznak, M. J., O’Connor, T. J., Boninger, M. L., &
Orthopädie und ihre Grenzgebiete, 123, 235–238.
Jones, D. K. (1998). Braking electric-powered wheelchairs: Effect of
Kolich, M. (2003). Automobile seat comfort: Occupant preferences vs.
braking method, seatbelt, and legrests. Archives of Physical Medicine
anthropometric accommodation. Applied Ergonomics, 34, 177–184.and Rehabilitation, 79, 1244–1249.
Koo, T. K., Mak, A. F., & Lee, Y. L. (1996). Posture effect on seating
de Looze, M. P., Kuijt-Evers, L. F., & van Dieen, J. (2003). Sitting comfort
interface biomechanics: Comparison between two seating cushions.
and discomfort and the relationships with objective measures.Archives of Physical Medicine and Rehabilitation, 77, 40–47.Ergonomics, 46, 985–997.
Kosiak, M. (1959). Etiology and pathology of ischemic ulcers. Archives of
Douglas, W. S., & Simpson, N. B. (1995). Guidelines for the manage-
Physical Medicine and Rehabilitation, 40, 62–69.
ment of chronic venous leg ulceration: Report of a multidisciplinary
Kosiak, M. (1961). Etiology of decubitus ulcers. Archives of Physical
workshop. British Journal of Dermatology, 132, 446–452.Medicine and Rehabilitation, 42, 19–29.Tilt, Recline, and Elevating Legrests for Wheelchairs
Kreutz, D. (1997, March). Power tilt, recline or both. Team Rehab
Reinecke, S., Bevins, T., Weisman, J., Krag, M., & Pope, M. (1985, June).The relationship between seating postures and low back pain. Paper
Kroemar, R. (1994). Sitting at the computer workplace. In R. Leuder &
presented at the annual meeting of the Rehabilitation Engineering
K. Noro (Eds.), Hard facts about soft machines: The ergonomics of
Society of North America, Memphis, TN.sitting (pp. 181–191). London: Taylor & Francis.
Reinecke, S. M., Hazard, R. G., & Coleman, K. (1994). Continuous
Kumar, S. (2004). Ergonomics and biology of spinal rotation. Ergonomics,
passive motion in seating: A new strategy against low back pain.Journal of Spinal Disorders, 7, 29–35.
Lacoste, M., Weiss-Lambrou, R., Allard, M., & Dansereau, J. (2003).
Reyes, M. L., Gronley, J. K., Newsam, C. J., Mulroy, S. J., & Perry, J.
Powered tilt/recline systems: Why and how are they used? Assistive
(1995). Electromyographic analysis of shoulder muscles of men with
Technology, 15, 58–68.
low-level paraplegia during a weight relief raise. Archives of Physical
Landis, E. (1930). Micro-injection studies of capillary blood pressure in
Medicine and Rehabilitation, 76, 433–439.
human skin. Heart, 15, 209–228.
Salomon, J., Denys, P., Merle, C., Chartier-Kastler, E., Perronne, C.,
Lange, M. (2000a, May 8). Tilt and recline systems. OT Practice, pp. 21–22.
Gaillard, J. L., et al. (2006). Prevention of urinary tract infection in
Lange, M. (2000b). Tilt in space versus recline: New trends in an old
spinal cord-injured patients: Safety and efficacy of a weekly oral
debate. Technology Special Interest Section Quarterly, 10(2), 1–3.
cyclic antibiotic (WOCA) programme with a 2 year follow-up—An
Lange, M. (2006, March). Positioning: It’s all in the angles. Advance for
observational prospective study. Journal of Antimicrobial Chemo-Occupational Therapy Practitioners, pp. 42.
therapy, 57, 784–788.
Levy, C., Berner, T. F., Sandhu, P. S., McCarty, B., & Denniston, N. L. (1999).
Sommerfreund, J., & Masse, M. (1995, October). Combining tilt and
Mobility challenges and solutions for fibrodysplasia ossificans progressiva.
recline. Team Rehabilitation Report, pp. 18–20.Archives of Physical Medicine and Rehabilitation, 80, 1349–1353.
Sprigle, S. (2000). Prescribing pressure ulcer treatment. Rehabilitation
Lueder, R. (2005). Ergonomics review. Retrieved from http://
Management, 13(5), 72–77.
www.humanics-es.com/ergonomics_movement.htm
Sprigle, S., Dunlop, W., & Press, L. (2003). Reliability of bench tests of
Nachemson, A. (1981). Disc pressure measurements. Spine, 6, 93–97.
interface pressure. Assistive Technology, 15, 49–57.
Nwaobi, O. M. (1987). Seating orientations and upper extremity function
Stinson, M. D., Porter-Armstrong, A., & Eakin, P. (2003). Seat-interface
in children with cerebral palsy. Physical Therapy, 67, 1209–1212.
pressure: A pilot study of the relationship to gender, body mass
O’Brien, J. G., Chennubhotla, S. A., & Chennubhotla, R. V. (2005).
index, and seating position. Archives of Physical Medicine and Reha-
Treatment of edema. American Family Physician, 71, 2111–2117.bilitation, 84, 405–409.
Paralyzed Veterans of America. (2000). Pressure ulcer prevention and
Ten Harkel, A. D., Van Lieshout, J. J., & Wieling, W. (1992). Treatment of
treatment following spinal cord injury: A clinical practice guideline
orthostatic hypotension with sleeping in the head-up tilt position,
for health care professionals. Retrieved from http://www.pva.org/
alone and in combination with fludrocortisone. J Internal Medicine,
Pellow, T. R. (1999). A comparison of interface pressure readings to
Trail, M., Nelson, N., Van, J. N., Appel, S. H., & Lai, E. C. (2001). Wheel-
wheelchair cushions and positioning: A pilot study. Canadian Journal
chair use by patients with amyotrophic lateral sclerosis: A survey of
of Occupational Therapy, 66, 140–149.
user characteristics and selection preferences. Archives of Physical
Pfaff, K. (1993, October). Recline and tilt: Making the right match. TeamMedicine and Rehabilitation, 82, 98–102.Rehabilitation Report, pp. 23–27.
Vaisbuch, N., Meyer, S., & Weiss, P. L. (2000). Effect of seated pos-
Porter, J. M., & Gyi, D. E. (2002). The prevalence of musculoskeletal troubles
ture on interface pressure in children who are able-bodied and
among car drivers. Occupational Medicine (London), 52, 4–12.
who have myelomeningocele. Disability and Rehabilitation, 22,
Porter, J. M., Gyi, D. E., & Tait, H. A. (2003). Interface pressure data and
the prediction of driver discomfort in road trials. Applied Ergonomics,
Wyndaele, J. J. (2002). Intermittent catheterization: Which is the optimal
technique? Spinal Cord, 40, 432–437.B. E. Dicianno et al.